The ones who idley stood by while that guy attacked people with a machete last year?
To be fair they don't even have non-lethal armaments, but it does again point to how useless the operation is in the face of a person who isn't just mad because their flight is delayed.
Core problem: how do you measure effectiveness of deterrent methods.
Actual or avoided incidents? Feeling of safety of the public? Most likely how happy the insurance companies are afaict
Well us who like the scientific approach would have incrementally added layers to the security onion, but in the real world, that kind of trial and error costs human lives.
Makes testing expensive
I hope you don't mean the unarmed minimally trained TSA staff that earn next to minimum wage. I highly doubt they'll protect you over themselves. Hell, many of them are obese (this is America) and physically unable to engage in such a scenario.